LINQ to SQL - Primary/Foreign key setup

Question

I'm trying to put a photo album in my app AND learn MVVM and LINQ and database interaction in C# all at the same time. I'm having issues with the DB, specifically, setting up the keys.

My error is this:

Additional information: Could not find key member 'PhotoID' of key 'PhotoID' on type 'Album'. The key may be wrong or the field or property on 'Album' has changed names.

I changed some things around hoping to fix it, but that did not work. My problem stems from not understanding EntitySet and EntityRef well enough, I believe.

Edit:

[Table]
public class Album : BaseModel
{

    // Version column aids update performance.
    [Column(IsVersion = true)]
    private Binary _version;

    private int _albumID;

    [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
    public int AlbumID
    {
        get { return _albumID; }
        set
        {
            if (_albumID != value)
            {
                NotifyPropertyChanging();
                _albumID = value;
                NotifyPropertyChanged();
            }
        }
    }
private EntitySet<Photo> _photos;
    //Proxy Class used to get pickuplines related to the category
    //OtherKey = ForeignKey
    //ThisKey = PrimaryKey
    [Association(Storage = "_photos", OtherKey = "AlbumID", DeleteRule = "CASCADE", ThisKey = "PhotoID")]
    public EntitySet<Photo> Photos
    {
        get { return _photos; }
        set
        {
            this._photos.Assign(value);
        }
    }




[Table]
public class Photo : BaseModel
{

    // Version column aids update performance.
    [Column(IsVersion = true)]
    private Binary _version;

    private int _photoID;

    [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)]
    public int PhotoID
    {
        get { return _photoID; }
        set
        {
            if (_photoID != value)
            {
                NotifyPropertyChanging();
                _photoID = value;
                NotifyPropertyChanged();
            }
        }
    }
[Column]
    internal int _albumID;

    private EntityRef<Album> _album;
    // ForeignKey
    // Proxy Class for the PrimaryKey Class
    // ThisKey = ForeignKey
    // PtherKey = PrimaryKey
    [Association(Storage = "_album", ThisKey = "AlbumID", DeleteRule = "CASCADE", OtherKey = "PhotoID", IsForeignKey = true)]
    public Album Album
    {
        get { return _album.Entity; }
        set
        {
            NotifyPropertyChanging();
            _album.Entity = value;
            if (value != null)
            {
                _albumID = value.AlbumID;
            }
            NotifyPropertyChanged();
        }
    }

Answer 1

In your Album association, you specify the AlbumID foreign key, but no such property exists in your entity. You have to expose a public property of it in your Photo entity.

private int _albumID;

[Column(CanBeNull = false)]
public int AlbumID
{
    get { return _albumID; }
    set
    {
        if (_albumID != value)
        {
            NotifyPropertyChanging();
            _albumID = value;
            NotifyPropertyChanged();
        }
    }
}

More on associations:

http://msdn.microsoft.com/en-us/library/bb386950(v=vs.110).aspx

http://msdn.microsoft.com/en-us/library/bb386951(v=vs.110).aspx